<h:selectManyListbox JSF and Enums Class Cast error

Question

This drives me crazy, cannot find the error.

Here the xhtml page:

...


        

Answer 1

You can't use enums in combination with h:selectMany*** components without using a converter. JSF/EL does not see/know the generic type of each of the separate list items. In other words, it only sees a List and not List<Severity> and treats every item as a String, unless you tell it to do otherwise.

You need to create and specify a converter yourself. For enums, it's the best to extend the JSF-provided EnumConverter.

package com.example;

import javax.faces.convert.EnumConverter;
import javax.faces.convert.FacesConverter;

@FacesConverter(value="severityConverter")
public class SeverityConverter extends EnumConverter {

    public SeverityConverter() {
        super(Severity.class);
    }

}

(note that when you're still using the old JSF 1.2, you should be declaring this as <converter> in faces-config.xml instead of by @FacesConverter)

Which you use as follows:

<h:selectManyListbox converter="severityConverter">

See also:

• How to use enums in select many menus?